Delivery/Recovery System for Septal Occluder

ABSTRACT

A delivery/recovery system to allow an operator to deploy and recover a medical implant, such as an occluder for closing a patent foramen ovale (PFO). In one embodiment, the system includes a delivery mandrel for preventing the occluder from moving in the proximal direction, a delivery wire for securing the occluder to the delivery mandrel and preventing unwanted movement in the distal direction, and a sheath for enveloping the delivery wire, mandrel and occluder. By moving the sheath relative to the occluder in a series of steps, the occluder opens first on a distal side and then on a proximal side, in a manner that holds the occluder in place.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 13/007,660 filed Jan. 16, 2011, now issued as U.S. Pat. No.8,568,431; which is a continuation application of U.S. application Ser.No. 11/070,027, now issued as U.S. Pat. No. 7,871,419; which claims thebenefit under 35 USC §119(e) to U.S. Application Ser. No. 60/569,422filed May 7, 2004 and U.S. Application Ser. No. 60/549,741 filed Mar. 3,2004, both now expired. The disclosure of each of the prior applicationsis considered part of and is incorporated by reference in the disclosureof this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an occlusion device for theclosure of physical anomalies like septal apertures, such as patentforamen ovale and other septal and vascular defects.

2. Background Information

A patent foramen ovale (PFO), illustrated in FIG. 1, is a persistent,one-way, usually flap-like opening in the wall between the right atrium11 and left atrium 13 of the heart 10. Because left atrial (LA) pressureis normally higher than right atrial (RA) pressure, the flap usuallystays closed. Under certain conditions, however, right atrial pressurecan exceed left atrial pressure, creating the possibility that bloodcould pass from the right atrium 11 to the left atrium 13 and bloodclots could enter the systemic circulation. It is desirable that thiscircumstance be eliminated.

The foramen ovale serves a desired purpose when a fetus is gestating.Because blood is oxygenated through the umbilical cord, and not throughthe developing lungs, the circulatory system of a heart in a fetusallows the blood to flow through the foramen ovale as a physiologicconduit for right-to-left shunting. After birth, with the establishmentof pulmonary circulation, the increased left atrial blood flow andpressure results in functional closure of the foramen ovale. Thisfunctional closure is subsequently followed by anatomical closure of thetwo over-lapping layers of tissue: septum primum 14 and septum secundum16. However, a PFO has been shown to persist in a number of adults.

SUMMARY OF THE INVENTION

Embodiments of a delivery/recovery system allow an operator to deployand, in many cases, recover a medical implant, such as an occluder forclosing a PFO. In one embodiment, the system includes a delivery mandrelfor preventing the occluder from moving in the proximal direction, adelivery wire for securing the occluder to the delivery mandrel andpreventing unwanted movement in the distal direction, and a sheath forenveloping the delivery wire, mandrel and occluder. By moving the sheathrelative to the occluder in a series of steps, the occluder opens firston a distal side and then on a proximal side, in a manner that locks theoccluder in place.

In this embodiment, the system preferably further includes a recoverycatheter with claws that can be controlled to grasp a partially deployedoccluder and withdrawing the occluder back into the sheath forrepositioning or removal.

A handle can be provided for assisting the operator with manipulationsto deliver and/or recover an occluder. The handle can include springsfor biasing the mandrel and sheath, with knobs for holding thesecomponents in desired positions.

The system can be used with a PFO occluder, such as an occluder with acenter joint for passing through the PFO tunnel, and closure componentson the distal (left atrial) side and on the proximal (right atrial)side. The closure components can include loops, open ended struts, orstruts that double back from the center joint to an end of the occluder.The occluder preferably also has a catching structure for holding thecomponents in place. The occluder can be made of a polymer, nitinol,stainless steel, or other suitable material, and can include a fabricfor promoting tissue growth.

The delivery/recovery system in the preferred embodiment provides aconvenient mechanism for delivering the occluder or other device, andfor recovering the device as needed. Other features and advantages willbecome apparent from the following detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a human heart with anatomical structures relevant to thisdescription.

FIG. 2 is a cross-section of a clover leaf occluder and adelivery/recovery system in its “stowed” configuration.

FIGS. 3, 4, 5A, 5B and 5C are cross-sectional views that illustrate asequence of events for using the recovery/delivery system to deploy theclover leaf occluder within the PFO.

FIGS. 6, 7, 8, 9, 10 and 11 are cross-sectional views that illustrate asequence of events for using the delivery/recovery system to recover adeployed occluder.

FIG. 12 shows an occluder deployed as described herein.

FIGS. 13 and 14 show an occluder with a locking member having a thirdstop between the end stops.

FIGS. 15, 16 and 17 show an occluder with a locking member as in FIG.13, in three stages of deployment.

FIGS. 18A and 18B show another embodiment of the mandrel tip.

FIGS. 19A and 19B show several alternative embodiments of the mandreltip.

FIG. 19C shows another alternative embodiment of the mandrel tip.

FIGS. 19D, 19E and 19F show several embodiments of the distal end of thewire for use with the mandrel tip of FIG. 19C.

FIG. 19G shows a mandrel with a soft segment added near its distal end.

FIG. 20 shows a handle for use with the occluder delivery/recoverysystem of FIG. 2.

FIGS. 21, 22, 23, 24 and 25 show stages of a delivery sequence using thehandle of FIG. 20.

FIGS. 26, 27, 28, 29 and 30 show stages of a recovery sequence using thehandle of FIG. 20.

FIGS. 31A and 31B show another embodiment of an occluder that may beused with some of the delivery systems herein.

FIGS. 32, 33, 34, 35, 36, 37, 38 and 39 show several views of anotheroccluder.

FIGS. 40, 41, 42, 43, 44 and 45 show several further embodiments ofoccluders.

FIGS. 46, 47 and 48 show still further embodiments of occluders, thesewith an end cap lock stop.

DETAILED DESCRIPTION OF THE INVENTION

The described embodiment is a delivery/recovery system for deployingand/or removing a device for occluding an aperture within body tissue.In particular and as described in detail below, an occluder may be usedfor closing a PFO in the atrial septum of a heart. Application Ser. No.10/890,784, filed Jul. 14, 2004, which is incorporated herein byreference, provides a more detailed description of an occluder that thedescribed embodiment manipulates. This occluder has a center joint,opposite ends, and loops extending from the center joint to the endssuch that the loops are generally parallel to the PFO tunnel. Because ofits shape, the occluder is referred to as a “clover leaf” occluder.

Although the embodiments described herein refer to a PFO in particular,the devices and methods of these embodiments may be used to treat otheranatomical conditions, such as an atrial septal defect (ASD) orventricular septal defect (VSD). As such, the invention should not beconsidered limited to any particular anatomical condition. Similarly,although the embodiments described herein refer to a clover leafoccluder in particular, the devices and methods of these embodiments maybe used to deploy other occluders, and other implants in general. Assuch, the invention should not be considered limited to any particulardeployable implants. For example, an occluder can include struts thatextend out in a manner like an umbrella, or can have struts that doubleback from a center joint to ends, with loops that are perpendicular tothe PFO tunnel. As used herein, the term “operator” means the personoperating the delivery/recovery system to insert an occluder into thebody of a patient.

FIG. 1 illustrates a human heart 10, having a right atrium 11 and a leftatrium 13. The atrial septum 12 includes septum primum 14, septumsecundum 16, and a passage 18 between the right atrium 11 and leftatrium 13. The anatomy of the septum varies widely within thepopulation. In some people, septum primum 14 extends to and overlapswith septum secundum 16. The septum primum 14 may be quite thin. When aPFO is present, there is a chance that blood could travel through thepassage 18 between septum primum 14 and septum secundum 16 (referred toas “the PFO tunnel”). FIG. 1 further shows an outline of thedelivery/recovery system 100, described herein, being inserted into theright atrium 11 through the inferior vena cava 20.

As shown in FIG. 2, a clover leaf occluder delivery/recovery system 100includes a clover leaf occluder 102, a delivery wire 104, a mandrel tip106, a mandrel 108, a recovery catheter 110, recovery claws 112, adelivery/recovery sheath 114, and a catch member 116 of the clover leafoccluder. The delivery/recovery system also includes a handle (notshown) that enables the operator to repeatably and efficiently performthe steps described herein. The handle is described in more detail inthe sections to follow. The occluder 102 and all components of thedelivery/recovery system 100 may be advanced into the sheath 114 afterthe sheath 114 has crossed the PFO 18, and the guide wire has beenremoved from the sheath 114.

FIG. 2 shows the clover leaf occluder delivery/recovery system 100 inits “stowed” configuration, i.e., as it is arranged when it is ready tobe inserted into a patient. The delivery wire 104, the mandrel 108, therecovery catheter 110, and the delivery/recovery sheath 114 are alldisposed in a coaxial arrangement about a longitudinal central axis,with the mandrel 108 disposed about the delivery wire 104, the recoverycatheter 110 disposed about the mandrel 108, and the delivery/recoverysheath 114 disposed about the recovery catheter 110. The mandrel tip 106refers to the distal end of the mandrel 108. The mandrel 108 extendsthrough the occluder 102 so that the mandrel tip 106 is disposed at thedistal end of the catch member 116. The delivery wire extends throughthe mandrel and out of the mandrel tip 106, and is bent at its distalend to form a hook. The bent end of the delivery wire rests against thedistal end of the locking member and provides a restraining force forpreventing the catch member 116 from moving in the distal direction.

In one embodiment, the mandrel 108 includes a portion at the distal endthat has a smaller outside diameter, creating a shoulder at thetransition. The smaller outside diameter portion fits through the catchmember 116, and the shoulder provides a stop against which the proximalend of the catch member 116 rests. The shoulder therefore preventsmovement of the catch member 116 in the proximal direction. In analternative embodiment, the mandrel 108 has an outside diameter slightlyless than the inside diameter of the locking member, and includes aregion having an extended outside diameter for providing a stop (i.e., abump) against which the proximal end of the locking member 116 rests, toprevent movement of the catch member in the proximal direction.

The recovery claws 112 are attached to the distal end of the recoverycatheter 110, and are spring loaded to tend toward opening, i.e.,expansion away from the central axis. The distal end of the catch member116 is fixedly attached to the distal end of the occluder 102.

FIGS. 3, 4, 5A, 5B and 5C illustrate a sequence of events for using therecovery/delivery system 100 to deploy the clover leaf occluder 102within the PFO tunnel 18. FIG. 3 shows a sheath 114 inserted into thePFO tunnel, with the occluder 102 partially deployed on the left atrialside of the PFO tunnel 18. The operator causes the occluder 102 to exitthe sheath 114 by moving the sheath relative to the occluder, preferablyby pulling the sheath 114 away from the distal end, while maintainingthe mandrel 108 and delivery wire 104 relatively fixed. Once the sheath114 uncovers approximately one half of the occluder 102, the cloverpetals of the occluder 102 are free to expand away from the central axison the left atrial side of the PFO 18. The operator pushes the sheathrelative to the mandrel 108 and the wire 104, further forcing the cloverpetals open to extend outwardly in a radial direction (an example inpartially deployed form is shown in FIG. 15, with full deployment inFIG. 17). This movement also pushes a central portion 136 of theoccluder 102 over the larger diameter proximal end 130 of the lockingmember.

Referring to FIG. 4, the operator again moves the sheath 114 relative tothe mandrel 108 and the wire 104, preferably by pulling back on thesheath 114, thereby uncovering the proximal petals of the occluder 102in the right atrium 11 and allowing these petals to expand away from thecentral axis. The operator then pushes the sheath 114 relative 20 to themandrel 108 and wire 104 further forcing those clover petals to extendoutwardly in a radial direction on the right atrial 11 side of the PFO18. The operator continues to push the sheath relative to the mandrel108 and wire 104, forcing the proximal end of the occluder over theproximal end of the catch member 116, thereby holding the occluder 102in its deployed position.

At this time the operator pulls the sheath 114 relative to the mandrel108, away from the deployed occluder 102, as shown in FIG. 5A.Withdrawing the sheath 114 from the occluder 102 provides theflexibility necessary to pivot the occluder 102 via the mandrel 108 to adesired position. The operator can then determine whether the occluder102 is properly deployed with respect to the PFO tunnel 18, usingtechniques such as transesophageal or intracardiac echo, and/orfluoroscopy. If the operator deems the occluder 102 to be properlydeployed, the operator pulls on the delivery wire 104 while holding themandrel 108 in a fixed position. If the operator pulls the delivery wire104 with sufficient force, the bend at the distal end of the deliverywire 104 straightens against the mandrel tip 106, and the wire 104withdraws into the mandrel 108 (FIG. 5B). Once the bend in the distalend of the wire 104 is gone, there is no longer a restraining forcepreventing the catch mechanism 116 from moving in the distal direction,and the operator disengages the mandrel 108 from the catch member 116(FIG. 5C). Alternatively, the operator could straighten the bend in thewire 104 by holding the delivery wire 104 in a fixed position andpushing on the mandrel 108, or by a combination of pulling on the wire104 and pushing on the mandrel 108.

If, after withdrawing the sheath 114 and manipulating the occluder 102as described above (FIG. 5A), the operator decides the occluder 102 isnot properly deployed, the operator can perform a recovery and/orrepositioning procedure. FIGS. 6 through 11 illustrate a sequence ofsteps described in detail below. From the position shown in FIG. 5A, theoperator pushes longitudinally on the recovery catheter 110 with respectto the sheath 114. Doing so causes the sheath 114 to uncover therecovery claws 112, removing a restricting force from the spring-loadedrecovery claws 112, and allowing the claws 112 to expand away from thecentral axis, as shown in FIG. 6. The operator continues to push therecovery catheter 110 relative to the sheath until the claws 112surround the proximal end of the occluder 102. The operator then pushesthe sheath 114 longitudinally relative to the recovery catheter 110until the sheath covers the claws 112, thereby closing the claws 112 onthe proximal end of the occluder 102, as shown in FIG. 7.

With the claws 112 immobilizing the occluder 102 relative to therecovery catheter 110, the operator pushes the mandrel 108longitudinally relative to the recovery catheter 110, forcing theproximal stop 130 of the catch member 116 through the proximal end ofthe occluder 102 in a distal direction, as shown in FIG. 8. As theoperator continues to push the mandrel 108 relative to the recoverycatheter 110, the mandrel 108 pushes the proximal stop 130 of the catchmember 116 through the occluder center joint 136, and the occluderelongates, so that the clover petals of the occluder retract toward thecentral axis, as shown in FIGS. 9 and 10. The operator pulls therecovery catheter 110 longitudinally relative to the sheath 114, so thatthe claws 112 pull the elongated occluder 102 back into the sheath 114.Once the sheath 114 covers the occluder 102, as shown in FIG. 11, theoperator can remove the delivery/recovery system 100 from the patient.

During this process, such as at points shown in FIG. 9, FIG. 10 or FIG.11, the operator can reverse course and deploy again as in the mannerdescribed in conjunction with FIGS. 3, 4 5A, 5B and 5C.

FIG. 12 shows an occluder 102 deployed as described above. The catchmember 116 in this embodiment includes a proximal stop 130 and a distalstop 132. The diameter A of the proximal stop 130 is greater than theinside diameter D of the occluder 102, and the diameter B of the distalstop 132 is greater than the diameter A of the proximal stop 130. Asdescribed herein, distal stop 132 should be fixedly connected to therest of the occluder and thus should not be movable with respect to theend of the occluder at any time, while the portions of the occluder moveover the proximal end to lock the occluder in place.

Referring to FIGS. 13 and 14, in another embodiment, the catch member116 a has a third stop 134 between the proximal stop 130 and the distalstop 132. The third stop 134 provides an intermediate stop for thecenter joint 136 of the occluder 102. The diameter A of the proximalstop 130 is greater than the inside diameter D of the occluder 102, thediameter B of the distal stop 132 is greater than the diameter A of theproximal stop 130, and the diameter C of the intermediate stop 134 isapproximately equal to the proximal stop 130. The third stop 134 allowsthe distal petals 138 of the occluder 102 to maintain their form priorto the engagement of the proximal stop 130, and in the event theproximal stop 130 fails.

FIGS. 15, 16 and 17 show a clover leaf occluder 102 in three stages ofdeployment with a three stop catch member 116 a. FIG. 15 shows theoccluder 102 with the distal end against the distal stop 132, FIG. 16shows the occluder 102 with the center joint locked with theintermediate stop 134, and FIG. 17 shows the occluder 102 completelydeployed with the distal end locked against the distal stop 132, thecenter joint 136 held against the intermediate stop 134, and theproximal end held against the proximal stop 130.

One embodiment includes a self-locking mandrel tip 106 a as shown inFIGS. 18A and 18B. This mandrel tip 106 a eliminates the need for a bendat the end of the delivery wire 104 by including an L-shaped extension140 that is preferably biased toward the center axis AX. When biased asshown in FIG. 18A, the mandrel tip 106 a can pass relatively unimpededthrough the axial passage in the catch member 116. When a straightdelivery wire 104 a is inserted through the mandrel 106 a as shown inFIG. 18B, the wire 104 a forces the L-shaped extension 140 away from thecenter axis and beyond the inside diameter envelope of the catch member.In this position, the L-shaped extension 140 impedes passage through thecatch member 116, and performs the same function that the bent wire 104provided in the earlier-described embodiment. Removing the wire 104 aallows the L-shaped extension 140 to return to its former biasedposition, again allowing relatively unimpeded passage through thelocking member 116.

Other alternative shapes for the mandrel tip 106 a are shown in FIGS.19A and 19B. All of these examples allow easier passage through thelocking member 116 without a delivery wire 104 a inserted than with adelivery wire 104 a inserted, and all of these examples operate withoutrequiring a bend in the distal end of the delivery wire and theassociated force required to remove it.

FIG. 19C shows another embodiment of a self-catching mandrel tip 106 chaving an aperture 150 in the side wall of the mandrel. The deliverywire 104 passes through this aperture 150 rather than extending outthrough the distal end of the mandrel as in the previously-describedembodiments. The distal end 152 of the delivery wire in this embodimenthas a hook that restricts the distal stop 132 of the catch member 116,and/or the distal end of the occluder 102, from movement in the distaldirection. Other possible shapes for the distal end 152 of the deliverywire 104 may also be used, for example those shown in FIGS. 19D, 19E and19F. The shape shown in FIG. 19F uses a wire that is thinner than theother embodiments shown, so that a pair of wires passes through themandrel. When pulling the delivery wire to release the implant from thesystem 100, the force required to “unbend” the hook is isolated to therim of the aperture 150. Since the mandrel is preferably made ofstainless steel or another similarly hard material, the rim of theaperture 150 can withstand that force without significant deformation.

FIG. 19G shows a mandrel with a soft segment 156 added near the distalend of the mandrel to improve pivoting between the delivery system andthe implant. In this embodiment, the soft segment is made of amartensitic or R-phase tube segment 156 attached to the proximal portion158 of the mandrel and the distal portion 160 of the mandrel via any ofseveral appropriate techniques known in the art. For example, a titaniumsleeve 162 may be used to attach the segment 156 via welding or crimpingto the proximal portion 158 and the distal portion 160 of the mandrel,as shown in FIG. 19G. The proximal portion 158 and the distal portion160 of the mandrel may be made of stainless steel to provide a more costeffective system than having the entire mandrel made of a martensitic orR-phase material (e.g., nitinol). Other metals and/or polymers mayalternatively be used to achieve similar results.

In contrast to occlusion devices made of materials such as nitinol,polymers typically produce recovery forces that are low and can beinsufficient to bring an implant device (e.g., an occluder) to itsdesired shape upon delivery without some assistance from the operator.The operator might have to manipulate several elements of thedelivery/recovery system. A handle 200 for this embodiment of anoccluder delivery/recovery system 100 performs many of thesemanipulations with minimal input from the operator, so that a polymermay be deployed almost as easily as, and in some cases easier than, ametal device. By carefully controlling and regulating the appliedforces, the handle 200 also protects the implant devices fromoverstressing that can occur with manual manipulations. Elements of thehandle also have general applicability to metal implant devices.

FIG. 20 shows a handle 200 for use with the occluder delivery/recoverysystem 100 described herein. The general procedure for inserting and/orremoving an implant is similar to that described in connection withFIGS. 3, 4, 5A, 5B, 5C, 6, 7, 8, 9, 10, 11, 12, 13 and 14, above. Thehandle 200 includes a delivery knob 202 attached to the sheath 114, andoperates between two primary positions, as further described herein. Aseparator 204 separates recovery and delivery springs, and provides asmall amount of compression to the springs in their most extendedconfiguration. A recovery knob 206 attaches to the recovery catheter 110and operates between two primary positions as further described herein.A mandrel knob 208 attaches to the mandrel 108 and operates between twoprimary positions, as further described herein. A delivery wire knob 210attaches to the delivery wire 104 and the mandrel 108. A delivery spring212 compresses between the delivery knob 202 and the separator 204, sothat withdrawal of the delivery knob 202 away from the occluder 202compresses the delivery spring 212. A recovery spring 214 is disposedbetween the recovery knob 206 and the separator 204, so that advancingthe recovery knob 206 toward the occluder 102 compresses the recoveryspring 214.

A handle housing 216 provides a casing for the other handle componentsand restricts their movements to within predetermined ranges. The casingmay have an ergonomic design so that the various components are easilyaccessible to the operator, and the required manipulations can beperformed in an efficient and repeatable manner.

A detachment screw 218 mates with the delivery wire knob 210, and isfixedly attached to the delivery wire 104. Rotating the detachment screw218 incrementally pulls on the delivery wire 104 with significant force,but in a controlled manner, pulling the bend in the distal end of thedelivery wire 104 against the mandrel tip 106, thereby straightening thebend and releasing the implant from the delivery/recovery system 100.

The delivery sequence for deploying an occluder 102 using the handle 200begins with the distal end of the delivery/recovery system 100 insertedthrough the PFO tunnel 18 from the right atrial side and extendedpartially into the left atrium 13. As used herein, the term “retract”means to pull away, longitudinally, from the distal end of thedelivery/recovery system 100. The term “advance” means to push,longitudinally, toward the distal end of the delivery/recovery system100. The operator begins the delivery sequence by retracting thedelivery knob 202 from position Ito position II, which compresses thedelivery spring 212 and uncovers the distal half of the occluder 102, asshown in FIG. 21. This allows the occluder clover petals to relax andpartially expand away from the central axis. The operator then releasesthe delivery knob 202, and the delivery spring 212 forces the deliveryknob 202 back to position I. The movement of the sheath 114 pressesagainst the clover petals, causing them to fully expand on the leftatrial side of the PFO, as illustrated in FIG. 22.

The operator again retracts the delivery knob 202 from position Itoposition II, uncovering the proximal half of the occluder 102, allowingthe proximal petals to expand partially away from the central axis, asshown in FIG. 23. The operator releases the delivery knob 202, thedelivery spring 212 forces the delivery knob 202 back to position I, andthe sheath 114 presses against the proximal occluder petals causing themto fully expand on the right atrial side of the PFO, as illustrated inFIG. 24. The sheath 114 pressing against the proximal occluder petalsforces the proximal end of the occluder 102 over the proximal stop ofthe catch member 116, thereby locking the occluder 102 in its deployedposition. The operator then retracts the delivery knob 202 to positionII and locks it into place (using a locking slot, a set screw, or someother similar locking mechanism known in the art). This retracts thesheath 114 away from the occluder 102, as shown in FIG. 25.

If the operator determines that the occluder 102 is in the properposition, the operator removes the bend in the distal end of thedelivery wire 104 by turning the detachment screw 218, which pulls thebend against the mandrel tip 106 and forces the bend to straighten. Theoperator then pulls the mandrel away from the deployed occluder 102 andremoves the delivery/recovery system 100 from the patient.

If the operator determines that the occluder 102 is not in the properdeployed position, the operator begins the recovery sequence byadvancing the recovery knob 206 from position III to position IV,compressing the recovery spring 214 and advancing the claws 212 outsideof the sheath 114 and toward the proximal end of the occluder 102. Theoperator then releases the delivery knob 202 from the locked position IIto position I, which forces the sheath 114 over the claws 112, clampingthe claws onto the proximal end of the occluder 102, as shown in FIG.26. The operator then advances the mandrel knob 208 from position V toposition VI, causing the mandrel 108 to push the proximal stop of thelocking member 116 through the proximal end of the occluder 102,unclamping the proximal part of the occluder 102 and allowing theproximal clover petals to elongate, as shown in FIG. 27. Note that oncethe occluder 102 is unclamped, the spring force of the compressedrecovery spring 214 pushes the recovery knob 206 from position IV toposition III, which causes the claws 112 to pull the proximal half ofthe occluder 102 into the sheath, along with the mandrel knob 208 fromposition VI to position V to completely withdraw the proximal petals ofthe occluder 102 into the sheath 114, as shown in FIG. 28. The operatorthen advances the mandrel knob 208 from position V to position VI, whichallows the distal petals of the occluder 102 to relax and elongate, asshown in FIG. 29. The mandrel knob 208 retracts automatically (viaspring force, or in some cases with assistance from the operator) fromposition VI to position V, withdrawing the occluder completely into thesheath 114, as shown in FIG. 30. The sheath may be left behind to allowfor another delivery. The operator may remove the recovered occluder 112and the delivery/recovery system 100 from the patient, or redeploy it.

The delivery system can be used with other embodiments that haveinternal interference catching systems. These systems typically includecomponents that pass through a center joint of an implant along alongitudinal axis. This type of catch member typically has a section orsections with a larger outside diameter (OD) than the inside diameter(ID) of the implant, so the catch member can engage the implant in oneof several ways, such as: (a) the section of the catch member with alarger OD compresses during the catching process as the catch memberpasses through the implant, and/or (b) the implant ID increases duringthe catching process as the catch member passes through the implant. Ineither case, a proximal tip of the catch member passes through theimplant device, the dimensions of both the device and the implant returnto more or less their original state, thereby holding the implant.Another option is that the catch member or part of the implant candeform temporarily to allow the catching member to pass through.

FIG. 31A illustrates another embodiment of a septal occluder that may bedelivered using a system of the type described herein. In this case, anoccluder 520 in a deployed position has a distal (left atrial) side 522and a proximal side 524, each with four petals. A catch mechanism 530has a distal ball 532, a proximal ball 534, and a rod 536 connectingballs 532 and 534. Balls 532, 534 and rod 536 can each have a centralbore (not shown) to allow catch mechanism 530 to be delivered withoccluder 520 over a guide wire, and can allow a bent wire to passthrough as in FIGS. 2 and 3. Other types of occluders, for example,those with petals having solid or mesh surfaces, or those with tissuescaffolds may also be used.

FIG. 31B is a side view showing occluder 520 with left atrial side 522and a right atrial side 524, each in contact with septum secundum 516and septum primum 514. In this figure, the catch mechanism is shown witha delivery wire 540 and sheath 542 in a connected position before thedelivery wire 540 would be detached from ball 534.

As described in the incorporated application Ser. No. 10/890,784, adevice of this type can be formed by making cuts or slits in a tube andcompressing the ends. The tube can be made of a polymer. In thisembodiment and others, the device can be made of a polymer that can bebioresorbable or not bioresorbable.

FIG. 32 shows an occluder with a ball and string for catching andholding a device mechanism. In the extended configuration for delivery(shown in FIG. 32 within a delivery sheath 1136), the distal ball 1130engages the distal joint 1110, and the proximal ball 1132 is disposedalong the delivery string 1134 between the distal joint 1110 and thecenter joint 1108. FIGS. 33, 34, 35 and 36 show the delivery sequencefor the ball and string mechanism of FIG. 32. A shown in FIG. 33, thedistal portion of the occluder is deployed from the delivery sheath 1136on the left atrial side of the PFO. FIG. 34 shows the proximal ball 1132pulled through the center joint 1108, thereby locking the distal portionof the occluder. FIG. 35 shows the proximal portion of the occluderdeployed from the delivery sheath 1136 on the right atrial side of thePFO. FIG. 36 shows the proximal ball 1132 pulled through the proximaljoint 1106, thereby locking the proximal portion of the occluder.Detaching wire 1134 from ball 1132 is the step remaining to complete thedelivery of the occluder in the PFO.

FIGS. 37, 38 and 39 show a recovery sequence for removing an occluder,such as that delivered in the manner shown in FIGS. 33, 34, 35 and 36.FIG. 37 shows the delivery sheath 1136 disposed against the proximal endof the occluder. Wire 1134 has been pulled with sufficient force to pullball 1130 through the distal joint 1110 thereby allowing the distal sideof the occluder to start to return toward a tubular shape. FIG. 38 showsthe distal ball 1130 further pulled through the center joint 1108, andup against the proximal joint 1106, so the right atrial side starts tolose its compressive force. FIG. 39 shows the unlocked occluder after ithas been retracted back into the delivery sheath and out of the PFO byadvancing the sheath, retracting the device, or some combination ofthese motions. Another method for recovering the device is using amethod similar to that shown in a provisional application entitled“Closure Device With Hinges”, provisional application No. 60/569,203,filed May 7, 2004, which is incorporated herein by reference. In thatmethod, a set of claws is used to grip and pull the device, startingwith the proximal joint.

In the embodiment of FIGS. 32, 33, 34, 35, 36, 37, 38 and 39 and inother embodiments, the balls need not be preferably spherical, but couldbe altered, such as having a distal ball with a flattened distal end. Aswith the delivery system of FIG. 2, the balls can have bores, and a bentwire or other mechanism can prevent the occluder from moving in a distaldirection when it is desirable to prevent such movement.

The following embodiments include “two elements” catching systems. Thetwo elements systems operate on the principle that two elements worktogether such that either one is small enough to pass through anoccluder center joint, but the two elements together form a unit that istoo big to pass through an occluder center joint.

FIGS. 40 and 41 show one type of two elements catching system, includingmultiple pairs of balls distributed along a pair of strings. In FIG. 40,a first ball 1360 and a second ball 1362 are fixedly attached to a firststring 1364 (or wire or suture). The distal end of the first string 1364is releasably attached to a ball 1365 that is part of the distal joint1110, either held to the distal end by the tension, or fixedly connectedto the distal end. The proximal end of the first string 1364 extends outthrough a center joint 1108 and a proximal joint 1106 to the operator. Athird ball 1366 and a fourth ball 1368 are fixedly attached to a secondstring 1370. The distal end of the second string 1370 is releasablyattached to the ball 1365 at the distal joint 1110, and the proximal endof the second string 1370 extends out through the center joint 1108 andthe proximal joint 1106 to the operator. The length of the first string1364 from the first ball 1360 to the distal joint is the same as thelength of the second string 1370 from the third ball 1366 to the distaljoint 1110. The length of the first string between the first ball 1360and the second ball 1362 is the same as the length of the second string1370 from the third ball 1366 to the fourth ball 1368. These lengthsensure that the first ball 1360 and third ball 1366 will be side by side(i.e., at the same point) along the longitudinal axis of the occluder,and the second ball 1362 and the fourth ball 1368 will be side by sidealong the longitudinal axis of the occluder. At least one of the stringscan be elastic, in this case string 1364, so that one of the strings maybe stretched to stagger the balls along the longitudinal axis, as shownin FIG. 40. Each of the strings 1364 and 1370 can include multiplestring segments. In each case, the strings can be fixedly connected tothe respective balls if a mechanism is provided to cut the strings afterdelivery.

To deploy the occluder, the operator pulls one of the strings in aproximal direction to stagger the first and third balls, and the secondand fourth balls. While the balls are staggered, the operator pulls bothstrings until the first ball 1360 and the third ball 1366 are on theproximal side of the center joint 1108, and the second ball 1362 and thefourth ball 1368 are on the proximal side of the proximal joint 1106.The operator then releases the string that is in elastic tension, so asto return the first/third and the second/fourth ball pairs in theside-by-side configuration. When the first/third ball and thesecond/fourth pairs are in side-by-side configuration, as shown in FIG.41, the pairs cannot pass through the center joints, thereby locking theoccluder. The strings are then detached or cut from the device tocomplete delivery.

To unlock the occluder before the delivery strings are detached, theoperator pulls on one of the strings to once again stagger the balls,thereby allowing the staggered balls to pass through the center joints.

Other embodiments may stagger the balls via other techniques. Forexample, the first string 1364 and second string 1370 may be onecontinuous string that passes through the distal joint and can slidealong a fixed or rotatable axle, so that the distal joint 1110 acts as apulley. The operator pulls on one of the strings to stagger or realignthe ball pairs.

FIGS. 42 and 43 show yet another two element catching system for anoccluder. A first ball 1380 and a second ball 1382 are fixedly attachedto a string 1384 (or wire, suture, or tube). The distal end of thestring 1384 is fixedly attached to a ball 1385 that forms part of thedistal joint 1110, and the proximal end of the string 1384 passesthrough the center joint 1108 and the proximal joint 1106 and out to theoperator. To deploy the occluder, the operator pulls the string 1384until the occluder stops against a delivery sheath 1386. The operatorcontinues to pull the string 1384 until the first ball 1380 is on theproximal side of the center joint 1108 and the second ball 1382 is onthe proximal side of the proximal joint 1106. The operator then insertsa rod 1388 through the proximal joint 1106, the center joint 1108, andthe distal joint 1110, as shown in FIG. 43. The outside diameter of therod 1388 is large enough to prevent either ball from passing through acenter joint while the rod 1388 is disposed within the center joints asshown in FIG. 43. Note that the string 1384 may include multiple stringsegments. The method of using claws, as referred to in conjunction withFIGS. 37, 38 and 39, could also be used here to recover the device.

FIGS. 44 and 45 illustrate another embodiment similar to that shown inFIGS. 42 and 43. A tube 1389 with an outside diameter slightly smallerthan the inside diameter of the center joints includes two apertures inthe side wall, each large enough for a first ball 1390 or a second ball1391 to pass. A string 1392 attaches the first ball 1390 to the secondball 1392. The operator deploys the occluder within the PFO by movingthe distal joint 1110 toward the proximal joint 1106, using any one ofseveral delivery techniques described herein or known in the art. Theoperator then inserts the rod 1393, thereby retaining each ball in itsrespective aperture. At least a portion of each ball extends beyond theoutside diameter of the locking tube 1389 in this position, preventingthe proximal joint 1106 from moving in the proximal direction or thedistal joint from moving in the distal direction, thereby locking theoccluder.

FIGS. 46, 47 and 48 show an embodiment of an end cap catching mechanism,including a catch member 1400 with a proximal ball 1402 fixedly attachedto its proximal end, and its distal end fixedly attached to the distaljoint 1110. This embodiment shows the distal end of the catch member1400 fixedly attached to a ball 1405 having an outside diameter largerthan the inside diameter of the distal joint 1110, although othertechniques of securing the distal end of the catch member 1400 to thedistal joint may also be used. The outside diameter of the proximal ball1402 may be slightly less than the inside diameter of the center joint1108 and the proximal joint 1106. A detachable delivery wire 1404 (ordelivery shaft) attaches to the proximal ball 1402, and a cap 1406 isdisposed about the delivery wire 1404 on the proximal side of thelocking ball 1402.

The operator engages this catch mechanism by pulling on the deliverywire 1404 so as to pull the distal joint 1110 in a proximal directiontoward the proximal joint 1106. Once the proximal ball 1402 is on theproximal side of the proximal joint 1106, as shown in FIG. 47, theoperator pushes the cap 1406 over the ball 1402. In order to passthrough the cap 1406 in the proximal direction, the ball 1402 deformscap 1406, expanding the inside diameter of the cap 1406. Once the ball1402 is through the cap locking 1406, the cap 1406 returns to itsoriginal shape, resisting the ball 1402 from passing back through thecap 1406 in a distal direction. The delivery wire 1404 is then detachedfrom ball 1402 if releasably attached to it, or is cut to sever theconnection to ball 1402.

In one embodiment, the cap has threads on its distal side, so that thecap 1406 can be screwed onto mating threads disposed on the outside ofthe proximal portion of the proximal joint 1106. In other embodiments, aclaw can be used to grip the ball 1402.

Having described several embodiments, it should be apparent thatmodification can be made and be within the scope of the appended claims.For example, other shapes and materials can be used.

What is claimed is:
 1. A delivery system for delivering a medical deviceto a living body, the device adapted to be elongated along an axialdirection when in the sheath in a delivery position, the deviceincluding one or more expanding portions that expand in a radialdirection perpendicular to the axial direction when delivered to form adeployed configuration, the device further including means for holdingthe device in the deployed position when the device is in the livingbody, the system comprising: means for limiting movement by the devicein the proximal direction; means for limiting movement by the holdingmeans in the proximal direction; means for limiting movement by thedevice in a distal direction; and means for enveloping the threelimiting means; the three limiting means and the enveloping means beingmovable relative to each other and to the device in a series of stepsfor allowing the expanded portions of the device to expand, and for theholding means to hold the device in its expanded configuration when inthe deployed configuration.
 2. The delivery system of claim 2, incombination with the device.
 3. The delivery system of claim 1, whereinthe holding means comprises a catheter.
 4. The delivery system of claim3, wherein the limiting means comprises a catch mechanism for holdingthe device in the deployed position when in the living body.
 5. Thedelivery system of claim 4, wherein the limiting means further comprisesa mandrel.
 6. The delivery system of claim 1, wherein the envelopingmeans comprises a sheath.
 7. The delivery system of claim 5, wherein thedelivery system further includes springs for biasing the catheter andmandrel, wherein controlling the positions of the springs allows fordelivery and withdrawal of the delivery system.
 8. The delivery systemof claim 5, wherein the mandrel extends along an axial direction andthrough the catheter and at least a portion of the device and forcontacting the catch mechanism at a proximal end of the catch mechanismfor limiting movement by the catch mechanism in the proximal direction.9. The delivery system of claim 5, further comprising a wire extendingalong the axial direction and through the catheter, the mandrel, and thedevice, the wire including a distal end that extends beyond a distal endof the device and that is adapted for limiting movement by the device inthe distal direction, the wire being removable while the mandrel isstill in contact with the catch mechanism.
 10. The delivery system ofclaim 2, wherein the device is a septal occluder.
 11. The deliverysystem of claim 10, wherein the septal occluder includes one of apolymer, nitinol, or stainless steel.
 12. The delivery system of claim11, wherein the occluder is at least partly made of a bioresorbablepolymer.
 13. The delivery system of claim 10, wherein the occluderincludes a fabric for promoting tissue growth.
 14. The delivery systemof claim 10, wherein the septal occluder has a center joint for passingthrough a PFO tunnel, and wherein, when delivered, the expandedcomponents include a first portion on a distal (left atrial) side of thePFO and a second portion on a proximal (right atrial) side of the PFO.15. The delivery system of claim 14, wherein at least one of theexpanded portions of the septal occluder includes one of loops, openended struts, or struts that double back from the center joint to an endof the occluder.
 16. The delivery system of claim 6, wherein the septaloccluder includes loops that are in a plane substantially parallel tothe tunnel for contacting the septum along the lengths of the loops.